Ditching and terracing level.



PATENTED MAR. 28, 1905.

E. A. BOSTROM. DITGHING AND TERRAOING LEVEL.

v APPLICATION FILED AUG.11, 1904.

2 SHEETS-SHEET l.

Inventor Hctomegs No. 786,093. 4 PATENTED MAR. 28, 1905. E. A. BOSTROM.

DITOHING AND TERRAGING LEVEL.

APPLIGATIION FILED AUG.11, 1904.

2 SHBIITSSHEET 2.

f ,..f' A

Witnesses Fkttomegs UNITED STATES Patented March 28, 1905.

ERNST A. BOSTROM, OF ATLANTA, GEORGIA.

DITCHING AND TERRACING LEVEL.

SPECIFICATION forming part of Letters Patent No. 786,093, dated March28, 1905.

Application filed August 11, 1904. Serial No. 220.398.

To all 1071/0721 7'15 Hui/y concern:

Be it known that I, ERNST A. Bosrnoiwna citizen of the United States,residing at Atlanta, in the county of Fulton and State of Georgia,

have invented a new and useful Ditching and wherein the turret carryingthe sighting-tube may be readily and accurately adjusted upon itssupporting ring or base and securely clamped in position to preventaccidental dislodgment, one wherein the construction of the turret willbe generally improved and simplified, one in which the construction andmanner of mounting the turret-supporting ring or base is improved andsimplified, and one wherein the spirit-level and sighting-tube aremounted and sustained in the turret in a simple efficient manner whichpermits of their ready adjustment.

To these ends the invention comprises the novel features of constructionand combination of parts more fully hereinafter described.

In the accompanyingdrawings, Figure 1 is a vertical sectional elevationof the improved device complete. Fig. 2 is a plan view of the devicewith the turret and its attendant parts removed. Fig. 3 is a top planView of the turret with the sighting-tube and spirit-level in position.Fig. 4'is a sectional elevation taken on the line 4 A of Fig. 3.

Referring to the drawings, 1 designates the primary supporting member orhead, preferably in the form of a horizontal disk-like plate, providedupon its upper face with a plurality of (preferably three) ballprojections 2, arranged marginally around the plate atappropriately-spaced intervals, while upon the under side of thesupporting-plate is a depending internally-threaded hollow boss 3,designed for the reception of the central screw or stem arising from thehead of a tripod.

4, preferably in the form of a horizontal ring or annulus havingdisposed centrally therein a bearing portion or spider 5, permanentlyconnected with the ring 4 by three radial arms or webs 6, having upontheir upper faces and at the inner margin of the ring 4 raised orelevated bearing portions or faces 7, upon which the turret 8 seats andrests when in position, attention being directed to the fact that bythis construction the turret will be firmly and evenly supported, whileat the same time the area of the bearing-surface and the frictionbetween the parts is minimized, as is also liability of dust and otherforeign matters lodging and accumulating upon the bearing portions. Theturret 8 is, as in my former patent, in the form of a tubular body ofperfect circular or annular form and having its end edges faced offperfectly true and parallel one to another. In the present instance theinternal bosses of the former construction are dispensed with and theturret is provided instead with a pair of inwardly-projecting marginalflanges 9, which extend wholly around the interior of the turret andrespectively adjacent to and parallel with its end edges 10, whichnormally lie in a horizontal plane and either one of which may seat uponthe bearing portions 7 when the turret is in position upon thesupporting-platen. The turret has formed through its side wall atdiametrically opposite points a pair of openings or perforations 11 12for the reception of a sighting-tube 13 and of which the normallyrearward opening 12 is of elongated or elliptical form to permitadjustment of the tube through the medium of ad justing-scrcws 14:,arranged above and below the tube 13 through openings in the flanges 9,the ends of the screws being tapped into the wall of the tube. isproperly adjusted or sighted, as in my former patent, by manipulatingthe screws 1A and reversing the turret upon the platen 4 until the samesight-point is marked through the tube with the turret in eitherposition. For determining the proper rotation of the turret upon theplaten in projecting a horizontal plane there is provided upon the sidewall of the turret a pointer or vernier and It may be mentioned that thetube 13 upon the upper horizontal face of the ring 1 a graduated scale15, indicating degrees, and in which the graduations are arranged asillustrated in Fig. 2. while for retaining the turret upon the platen toprevent its accidental dislodgment and for securing it in adjustedpositions I employ a pair of shoulder-screws 16, engaged at their lowerends with the spider 5, and a clamp 17, carried by a clampingscrew 18,also extended through the spider, the heads of the screw 16 beingadapted to overlap the flange 9, with which latter the clamp alsoengages, it being apparent that by manipulating the milled nut upon theclamping-screw 18 the turret will be lixed against rotation.

The spider 5 has a central concaved portion or depression 19, centrallyof which there is disposed a screw or stem 20, tapped at its lower endinto the base 1, there being mounted upon the stem a spring 21, bearingat its upper end upon the head of the screw and at its lower end upon asemispherical bearing member or washer E22, seated in a correspondingrecess at the bottom of the depression 19, by which arrangement thesupporting ring or platen 1 will have substantially universal movementupon the supporting-head 1 and may thus be readily adjusted for truingthe turret and sighting-tube by means of adjusting-screws 23, tappedinto bosses 24:, formed upon the lowerface of the spider 5, the screwshaving at their lower ends sockets which receive the ball-heads 2,whereby the screws are likewise supported for universal movement uponthe base 1 and may thus readily conform to the movements of the platenin adjusting the latter.

ithin the turret 8 and parallel with the sighting-tube 13 there isvarranged a spiritlevel 25, the tube of which is adjustably sustained ateach end by means of upper and lower adjusting-screws 26, extendingloosely through the horizontal flanges 9 and tapped at their ends intothe wall of the tube.

' It is apparent from the foregoing that 1 produce a comparativelysimple device which in construction and operation is a decidedimprovement over my former patented device and one wherein the variousadjustments necessary to the operation of the mechanism may be readilyand quickly obtained. In attaining these ends it is to be understoodthat I do not wish to limit myself to the precise details herein setforth, inasmuch as minor changes may be resorted to without departingfrom the spirit of the invention.

Having thus described the invention, what is claimed is- 1. In a deviceot' the class described,a platen,

a turret supported thereon and having upper and lower inwardlyprojecting marginal flanges and a pair of opposite openings, a sighttubeextended through said openings, and adjusting-screws extended throughthe flanges for acting upon the tube.

2. In adevice of the class described,a platen, a turret seated thereonand having an internal flange, a sight-tube carried by the turret, andretaining devices carried by the platen and engaging the flange tomaintain the turret in position.

3. Inadeviceoftheclassdescribed, aplaten, a turret seated thereon andhaving an internal flange, a sight-tube carried by the turret, retainingmembers carried by theplaten for detachabl y engaging the turret-flange,and a clamping device also carried by the platen and engagingsaidflange.

4. In a device of the class described, asupporting-base, a platenarranged above the base and having a concavity, a stem arising from thebase within the concavity, asemispherical bearing member seated upon thestem within the concavity, adjusting screws in threaded engagement withthe platen and having universal-joint connections with the base, and aturret seated upon the platen.

In a device of the class described, a supporting base and platen, ayieldable universaljoint connection between said parts, adjusting-screwsin threaded engagement with one of the parts and having ball-and-socketconnection with the other, a turret seated upon the platen, a sight-tubecarried by the turret, and means carried by the platen and engaging theturret for clamping the latter in adjusted position.

6. In a device of the class described, a base, a platen connectedtherewith and comprising an outer ring, an inner spider, andconnecting-webs between the spider and ring, said webs being providednear the inner margin of the ring with raised portions or seats, aturret adapted to rest upon said seats, and a sighttube carried by theturret.

7. In a device of the class described, a platen, a reversible turretseated thereon and having upper and lower internal flanges, a sight-tubecarried by the turret, and retaining devices carried by the platen anddesigned for engagement with either of the flanges to maintain theturret in position.

In testimony that 1 claim the foregoing as my ownl have hereto aflixedmy signature in the presence of two witnesses.

ERNST A. BOSTROM.

Vitnesses: s

ROBERT W. MUNK, 'E. F. NAsH.

